prolonged from אֵם; properly, a mother (i.e. unit of measure, or the fore-arm (below the elbow), i.e. a cubit; also a door-base (as a bond of the entrance); cubit, [phrase] hundred (by exchange for מֵאָה), measure, post.
from טָפַח (the same as טֵפַח); {a spread of the hand, i.e. a palm-breadth (not 'span' of the fingers); architecturally, a corbel (as a supporting palm)}; hand-breadth (broad).
a primitive root; properly, to stretch; by implication, to measure (as if by stretching a line); figuratively, to be extended; measure, mete, stretch self.
TRV